rolling-updates.md

Rolling Updates

• Use multiple replication controllers with a single service
• Deploy a canary application for testing

Send the Canary

kubectl run inspector-canary \
  --labels="app=inspector,track=canary" \
  --replicas=1 \
  --image=b.gcr.io/kuar/inspector:2.0.0

Validation

Try hitting the service port on any of the node instances.

laptop

PROJECT_ID=$(gcloud compute ssh nginx --command \
  "curl -H 'Metadata-Flavor: Google' \
  http://metadata.google.internal/computeMetadata/v1/project/project-id")

while true; do curl -s "http://inspector.${PROJECT_ID}.io" | \
  grep -o -e 'Version: Inspector [0-9].[0-9].[0-9]'; sleep 1; done

Did you find the canary?

Rolling Update

Open three terminals

Terminal 1

laptop

kubectl get pods --watch-only

Terminal 2

laptop

PROJECT_ID=$(gcloud compute ssh nginx --command \
  "curl -H 'Metadata-Flavor: Google' \
  http://metadata.google.internal/computeMetadata/v1/project/project-id")

while true; do curl -s "http://inspector.${PROJECT_ID}.io" | \
  grep -o -e 'Version: Inspector [0-9].[0-9].[0-9]'; sleep 1; done

Terminal 3

laptop

kubectl rolling-update inspector --update-period=3s --image=b.gcr.io/kuar/inspector:2.0.0